's not yet possible to get the exact figures. u.s. military aircraft evacuated some survivors to a nato airbase in sicily. pictures of the siege show gunmen rounding up hostages. this b.p. worker says terrorists told him "you have nothing to do with this. you're algerians and muslims. we only want the foreigners." b.p. chief executive bob dudley said 14 of its 18 foreign employees at the plant were safe. >> we are not able to confirm the circumstances of four of our employees. tragically, we gravely fear that we will be seeing fatalities fatalities from this group. >> reporter: algerian troops discovered a cache of heavy machine guns, rocket launchers, and grenades. hostages said the explosives were wired around their necks. local media have identified this man, abdul rahman al-nigeri, as the leader of the attack. he's a lieutenant of mokhtar belmokhtar, head of an al qaeda-linked group based in north africa. the aljean state oil company running the plant said the attackers had the entire refinery booby trapped and it would be days before the clearing out process is complete. charlie d'